A biofilm reducing agent (BRA) and a mineral deposit distorting agent (MDDA) are admixed to irrigation water in amounts sufficient to substantially eliminate biofilm formation in the emitters (14) of an irrigation system (10) and produce amorphous mineral deposits in the emitters that are easily washed away by the irrigation water as it flows through the emitters (14). The BRA may be an oxidizer selected from the group consisting of chlorine, ozone, chlorine dioxide, hydrogen peroxide, hydroxy peracitic acid, iodine, bromine, hydrogen dioxide, chlorate salts, chlorite salts and hypochlorite compounds and mixtures thereof. The MDDA is a phosphonate selected from the group comprising AMP, ATMP, HEDP, EDTMPA, HMDTMPA, DETPMPA, BHMPTMPA, PBTC, HPA, PCA, NTMP, and DTPMP.